//Emil Fihlman
//gcc -Wall -Werror -Wextra -flto -O3 -o serial serial.c
#include <stdtypes.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <termios.h>
#include <sys/select.h>

void init(unsigned int baudrate, int serial, struct termios *terminal, struct termios *backup, struct termios *serialport)
{
	tcgetattr(0, backup);
	tcgetattr(0, terminal);
//	cfmakeraw(terminal);
	terminal->c_lflag&=~ICANON;
	terminal->c_lflag&=~ECHO;
	terminal->c_cc[VMIN]=1;
	terminal->c_cc[VTIME]=0;
	tcsetattr(0, TCSANOW, terminal);

	tcgetattr(serial, serialport);
	cfsetspeed(serialport, baudrate);
	cfmakeraw(serialport);
/*	serialport->c_cflag |= (CLOCAL | CREAD);
	serialport->c_cflag &= ~CSIZE;
	serialport->c_cflag &= ~CSTOPB;
	serialport->c_cflag |= CS8;
	serialport->c_cc[VMIN]=1;
	serialport->c_cc[VTIME]=0;
*/
	tcsetattr(serial, TCSANOW, serialport);
//	fcntl(serial, F_SETFL, FNDELAY);
}

int main(int argc, char *argv[])
{
	struct termios terminal={0}, backup={0}, serialport={0};
	unsigned char buf[1024];
	unsigned int baudrate=115200;
	int i,serial;
	fd_set set;
	if(argc<2)
	{
		fprintf(stderr, "Usage: %s path [baudrate]\n", argv[0]);
		return(1);
	}
	serial=open(argv[1], O_RDWR | O_NOCTTY | O_NONBLOCK);
	if(serial==-1)
	{
		fprintf(stderr, "Unable to open device %s\n", argv[1]);
		return(2);
	}
	if(argc>2)
	{
		baudrate=(unsigned int)strtoul(argv[2], NULL, 10);
		switch(baudrate)
		{
			case 50:
			case 75:
			case 110:
			case 134:
			case 150:
			case 200:
			case 300:
			case 600:
			case 1200:
			case 1800:
			case 2400:
			case 4800:
			case 9600:
			case 14400:
			case 19200:
			case 28800:
			case 38400:
			case 57600:
			case 76800:
			case 115200:
			case 230400:
			case 250000:
			case 500000:
			case 1000000:
			case 2000000:
				break;
			default:
				fprintf(stderr, "Unsupported baudrate %u\n", baudrate);
				return(3);
		}
	}
	init(baudrate, serial, &terminal, &backup, &serialport);
//	fprintf(stderr, "\e[?25l\n");
	while(1)
	{
		FD_ZERO(&set);
		FD_SET(0, &set);
		FD_SET(serial, &set);
		if(select(serial+1, &set, NULL, NULL, NULL)==-1)
		{
			break;
		}
		if(FD_ISSET(0, &set))
		{
			if((i=read(0, buf, 1))>0)
			{
				write(serial, buf, i);
			}
		}
		if(FD_ISSET(serial, &set))
		{
			if((i=read(serial, buf, 1))>0)
			{
				write(1, buf, i);
			}
		}
	}
	tcsetattr(0, TCSANOW, &backup);
	fflush(stdout);
//	fprintf(stderr, "\e[?25h");
	return(0);
}